Moving stairway



Aug. 30, 1938. s. G. MARGLES 2,123,310

Filed March 50, 1937 2 Shee s S e l Aug. 30, 1938. s. G. MARGLES 2,128,310

1 MOVING STAIRWAY Filed March 30, 1937 2 Sheets-Sheet 2 SW Quill W INVENTOR BY ATTORNEY Patented Aug. 30, 1938 UNITED STATES PATENT OFFICE MOVIN G STAIRWAY Samuel Gustave Marg'les, Brooklyn, N. Y., assignor to Otis Elevator Company, New York, N. Y., a corporation of New Jersey Application March 30, 1937, Serial No. 133,731 7 Claims. (01. 198-16) The invention relates to moving stairways. by the chain wheels on curved tracks as they Moving stairways comprise an endless series pass around the bend at the lower end of the of steps which are moved from one landing to stairway. another for the Purpose Of V y ng Pa s e s. As to the transition of the support of the steps The s p re Conne ted together by means Of at the top of the upper end of the stairway, the 5 sprocket chain, known as running gear chain. invention is applied to a stairway construction in It has been the practice for a considerable numwhich the chain wheels are outside the links of h f y s to p vide a running gear chain on the running gear chains, and is carried out by each side of the stairway and to drive these chains extending the horizontal portion of each of the 0 by means of sprocket wheels at the upper end of upper run chain wheel tracks up to a certain 10 the stairway. Each step is provided on each side point on the incline side of a vertical line through with a chain wheel associated with the running the center of the sprocket wheel and at such gear chain. Sprocket wheels may be provided at height that the axis of each of the chain wheels the lower end of the stairway for the chains to along this portion of the track is above a horicarry the steps around the bend or curved tracks zontal tangent to the pitch circle of the sprocket 15 may be provided for the chain wheels. It is dewheel and by sloping thetrack-gradually downsirable that moving stairways operate as smoothly wardly from such point past this vertical center and noiselessly as possible. Many improvements in such way that the line of travel of the axes of I have been made with the view of aiding in acthe chain wheels and the pitch circle of the Complishihg s pu p The s ep a s psprocket Wheel merge at a point on the bend. ported y t a s for the chain W eels as they Thus, in the case of an ascending stairway, the com-e up to the sprocket wheels at the end of the transition of the support of the step from the stairway. Also, the chain wheels pass onto tracks chain wheel tracks to the sprockets is effected to support the steps as the chains leave the gradually, the chain wheel rollers not fully seatsprocket wheels after the steps have passed ing on the sprocket wheels until after the chain 25 around the bend. One of the problems has been Wheels have passed a certain distance beyond the to provide a moving s w y construction in vertical center of the sprockets. In the case of a Which the transition of the Support Of t steps descending stairway, the transition from the from chain wheel tracks to the sprocket wheels wheels to the tracks is also efiected gradually, the

b0 and from the sprocket wheels to chain wheel lifting of the chain Wheel rollers from the tracks is efiected smoothly and with a minimum sprockets beginning a certain distance ahead of Of IlOiSe as the Steps p s a u he e at the this vertical center. Thus these transitions are end f t e s airw y, nd t maintain such per effected gradually and with a minimum of noise tion after wear of the chain wheels has taken for an extended period of tim W Of e Chain ewheels simply resulting in a recession toward the 35 0118 Object of h invention is o e m t vertical center of the sprocket wheel of the point noise incident to the transfer of e p r of at which the chain wheel rollers seat on or lift the steps from the upper run chain wheel tracks from the sprocket wheels. o the p k Wh as the steps start to p As to the transition of the support of the steps 40 around the bend when the stairway is moving in at th bottom of the upper end of the stairway, 40 one direction and from the sprocket wheels to the t tio is carried out by arranging each when the Stairway is moving in the other of the return run chain wheel tracks between dlrectlonthe incline and the sprocket on a curve, the di- A t? obJect of the mventlon is to ehmmate rection of curvature of which is opposite to that i.) noise incident to the transfer of the support of of the pitch circle of the sprocket WheeL The the steps from the sprocket Wheels to the curvature is such that the transition of the supof a is moving in one direction and from the tracks to w q i Is exerted on eac h Wheel the wheels when th tairway i moving in the to maintain it on the track after its chain roller 50 other direction. leaves the sprocket in the case of an ascending The invention will be described as applied to a rw y r un l i n s h spr i the moving stairway construction in which driving case of a descending stairway, so that the transisprockets for the chains are provided at the uption is made with a minimum of noise. Per end of t e. a w y Wi t Steps supported, Features and advantages of the invention will 55 be apparent from the following description and appended claims.

In the drawings:

Figure 1 is a diagrammatic representation in side elevation of a. moving stairway embodying the invention;

Figure 2 is illustrating one side of Figure 1 at the upper end thereof, shown diagrammatically;

Figure 3 is a side View of the mechanism for adjusting the upper run chain wheel tracks at the upper end of the stairway; and

Figure 4 is a section taken along the of Figure 3.

The stairway illustrated is of a present day commercial construction. It comprises an endless series of steps l driven at the upper end of the stairway by means of sprocket wheels through running gear chains, a sprocket Wheel and chain being arranged on each side of the stairway. A sprocket wheel ii and running gear chain l2 are illustrated for one side of the stairway. The sprocket wheels are mounted on and driven by the main drive shaft i5, driven in turn by driving mechanism (not shown).

Each step comprises a step frame l6 upon which the tread ll is mounted. The frame is mounted on brackets I8, one on each side of the stairway. The chain wheels for the step are mounted on an axle 2i extending across the stairway through opposite chain rollers in the running gear chains, the chain wheels being outside the links of the running gear chains. The axle extends into axle blocks 22 secured to one end of step bracket I8 at each side of the stairway. The axle blocks clamp the axle against rotation, the axle being preferably flattened at this point to aid in preventing its turning. Each of the trailer wheels 23 for the step is mounted on an axle 24 supported by the other end of the step bracket l8.

An upper run track 25and a return run track 25 are providedon each side of the stairway for the chain wheels. The chain wheels are illustrated as passing around the bend at the lower end of the stairway on curved end tracks 34. At the upper end of the stairway, each upper run track extends beyond the main drive shaft partially around the bend. The track is horizontal up to a point 21 to cause the step to be flat as it meshes with or emerges from the comb plate and is of such height as to cause the axes of the chain wheels along this horizontal portion of the track, the line of travel of which is indicated by the line 29, to be above a horizontal tangent 39 to the pitch circle 36 of the sprocket wheel. From this point on, the track extends gradually downwardly to a point 28 at such distance beyond a vertical line v-v through the center of the main drive shaft that the line 29 of travel of the axes of the chain wheels on the track and the pitch circle 30 of the sprocket Wheel merge on the radial line o-y extending from the center of the main drive shaft through point 28. The track terminates a short distance beyond this point, being flared at its end. The portion of the track between the points 21 and 28 is preferably the, arc of a circle of long radius swung from a point beneath the stairway with the center so located that the line of travel of the axes of the chain wheels on that portion of the track is tangent at one end to the pitch circle 30 and at the other end to the horizontal part of line 29.

Each of the return run tracks 26, in the conan enlarged view in vertical section the stairway shown in parts being struction illustrated, extends from the sprocket wheel on a curve 3!, the direction of curvature of which is opposite to that of the pitch circle 30 of the sprocket wheel, into the incline portion 32 of the return run track. Although the curved portion 3i of the track may be of other curvaturcs and other variations in the arrangements may be made, a suitable arrangement is had by swinging the curve on an arc of a circle of long radius.

that the to the curve at incline portion 32 of the track is tangent one end and at its other end the curve is tangent to an arc of a circle swung about the center of the main drive shaft.

The point 33 on the incline side of verthe center of the main of common tangency is tical line 11-12 through V drive shaft, being on the line 0-4: through the center of the main drive shaft and normal to the curve and at a distance from the center of the -main drive shaft to provide a slight operating clearance for the chain wheels.

An up thrust track 35 is provided on each side of the stairway for the chain wheels on the upper run. An out thrust track 36 is provided on each side of the stairway for the chain' wheels as they pass around the bend at the upper end. The out thrust tracks are concentric with the sprocket wheels. An up thrust track 31 is provided on each side of the stairway for the chain wheels on their return run. An out thrust track 38 is provided on each side of the stairway for the chain wheels as they pass around the bend at the lower end of the stairway. Each of the thrust tracks provides a small clearance for operation of the chain wheels.

The track system for the trailer wheels on each side of the stairway comprises an upper run track 4% having an up thrust track M, a return track d2 having an up thrust track 43, and an inner curved track 44 and outer curved track 45 at each end of the stairway for guiding the trailer wheels. around the bends. The tracks are positioned and shaped to give the proper position to the steps at the various points in their travel.

In the case of an ascending stairway, wheels run on their upper run tracks as they arrive at the upper end of the stairway, remaining on these tracks until the point 28 is reached. As this position is reached, the rollers in the running gear chains through which the chain wheel axle extends mesh with the sprocket wheels ll. With such construction, the steps are supported by the tracks up to this point and the transition of this support to the sprocket wheels is effected gradually, ing of the chain wheel rollers with the sprockets being eliminated. Thereafter the sprocket wheels carry the step around the bend to the point where the chain wheels run onto their return run tracks.

Each chain wheel on each side of the stairway remains in mesh with the sprocket wheel as the step passes around the bend until the axis of the chain wheel, the axis of the next succeeding chain roller and the axis of the chain wheel next ahead assume a straight line. occurs is determined by the radius'of curvature of the arcuate line 46 of travel of the axes of the chain wheels on curve 3 I. This radius may be the number of links in the running gear chain between chain wheels times the pitch radius of the sprocket wheel. With such construction, the straight line condition would occur as the axis of the chain wheel reaches the line 0-3:, or in other words when the chain wheel reaches the point 33 of common tangency. This is due to the factthat,

The center of the curve is chosen so the chain noise incident to the mesh The point at which this engage the upper. run tracks :25.

.after the aXisof the. chainzwheel passesLthe vvertical line v..o:thr0ugh 'the center-1of the sprocket wheel, the pull on the' chain, in maintaining the following chain roller in'mesh withits sprocket, raises the chain wheeleuntil thisrstraight jline condition is :reached. After .the straight 'Iline condition has beencreached, the" chain-wheel roller starts to leave the sprocketand as further movement of the chain'takes. place, the chain wheel is gradually. transferred to the return track, this taking place atthe point 41. From this point on, the chain Wheel ismaintained on'the return track, thecurvature of the curvedtrack portion 3| beingsuch'ias .to cause-the'pull on the chain 'eifecting the. transition of the chainwheelsto the return run .tracks,:the'steps are supported by thesprocket wheelsiin passing around the bend until after the chain wheels pass a-vertical plane through theunainldrive shaft and are thereafter gradually transferred to 'thereturn run tracks. Once the chain wheels engage these tracks; they are maintained'thereon so that a gradual and-yet positive transition is made, noiseincident to the transition being eliminated.

The reverse of the abovedescribed operations take place "in the .case of. .a descending stairway. Each of thechain wheels is maintained on the returnzrun'trackiuntil the point is reached. Thereafter it gradually leaves the track and when the straight line condition is assumed, the chain roller through which-the chain wheel axle extends meshes with the sprocket. Thereafter the sprockets carry the steps around the bend until the point 28 is reached,where the chain wheels Thereafter the chain'wheel rollers are gradually 'lifted o'iT the sprocket wheel. Thus, smooth and noiseless transition is made at the top and bottom of the upper end of the stairway regardless of whether the stairwayis an-ascending or'descending one.

This track construction insures a noiseless transition of the support of the .steps to the sprocket wheels from the tracks and from the sprocket wheels to the tracks after wear of'the chain wheels takes place. In case of an-ascending stairway, as soon as the chain'wheels start to wear, the chain rollers' throughwh-ich the chain wheel axle extends mesh with the sprocket wheels sooner in starting around the'bendand the chain wheels engage the return run i tracks later a after having passed. around the bend. In other words, the greater the wear on'the chain wheels, the sooner the chain rollers'mesh with the sprocket Wheels at the top and the later the wheels roll onto the returntracks-at the bottom. Incase of a descending stairway, the reverse is true, that is, the greater the wear on the chain wheels the sooner the chain wheels leave the returnrun tracks at the bottom andithelater the wheels roll onto the upper runtracks at the top.

An adjustment maybe providedfonthe upper '.:run tracks to raise them chain .wheel wear.

in adjusting block. 62

"scribed would be very infrequent, the

at their .ends, -th'ereby enabling thertracks to. be resetrafter periods. of An arrangement for-eflfecting this adjustmentis illustrated in somewhat simplified formflin Figures 3 and 4 for theupper run track Lon one side of the stairway, the arrange- .ment for the upper run track onthe otherside of the stairway being In this construc- 58 of the upper-run track the same. tion the end portion 254s securedasby welding to an angle 5| with a suitable elongated: spacer '52 betweenthem to provide operating clearance for the chain wheels and. axles. This end portion 56 is secured asby 'a bolt 53 to a bracket 54, in turn secured to a truss angle angle 5| extends beyond the flared end run track 25an'd at its-outer end has thereto a pair of small angles 58, one side of the angle.

of upper secured on each The end of angle 5| is supported by a cross angle 60 extending between truss angle .55 and a corresponding truss angle on the other side of the stairway. This support is effected by means of bolts 6! extending upwardly through angles 58 and cross angle 60. Secured as by welding to: the cross anglefiil on the underside thereof is an adjusting block 62 having threaded apertures 63 therein for receiving tubular jack screws 64 through which bolts tend. By moving the end of angle 5| in the proper direction, the outer end of the end'portioni -56 of upper run track Zia-may be set at the desired height, this arrangement being utilized for effecting the proper setting of the track upon the initial installation and for resetting the track after chain wheel wear has taken place.

Assume, for example, that the chain wheels on each sideof the stairway have Worn to such extent that, in an ascending stairway for example, the point at which the chain wheel rollers mesh with the sprocket wheel on each side ofthe stairway has moved back near the vertical line v-o through the center of the main drive shaft. By screwing the screw jacks 64 intotheir sockets and tightening up bolts fi I the outer end of each upper run track=is raised to bring the 'point at which the chain wheel rollers meshwith the sprocket wheelssay back to the point 28. This upward movement of the outer end of the track is effected by bending track portion about the point at which it is secured to bracket 54. By arrangingthehorizontal portion'of upper run track on each-side of the stairway at a suitable height, an arrangement is provided in which several years would elapse-in commercial operation before'the wear of the chain wheels would caus'e'the point at which the chain wheel rollers mesh 'with the sprocket'wheel to be near enough-to the line o-o for adjustment to be desirable. Thus the adjustments to insure theoperation -above-detrack construction itself automatically compensating for the wear which would occur between adjustments.

Although the invention has been describedas.

applied to a moving stairway arrangement in which the chain wheels pass around curved tracks at the lower end of the stairway, it is "to be understood that the'tracks at the lower end ofv the stairway may be arranged in accordance with the invention where sprocket wheels are utilized to carry the steps'around the bend. Also,

it is to be understood that the track arrangements described for'the upper end 'ofthe stairway may be varied-without departing from the invention. The invention may be applied to other forms of moving stairway construction, the form shown being chosen for convenience of illustration. The arrangement of track system for the trailer-wheels may be varied, the invention being applicable to various arrangements, includ ing, for example, those shown in the co-pending application of Samuel Gustave Margles and Andrew Fabula, Serial No. 143,652, filed May 20, 1937. The invention is applicable to one way stairways as well as reversible ones.

Therefore, as many apparently widely different embodiments of this invention may be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A moving stairway comprising; a series oi steps; a running gear chain connecting said steps together; a sprocket wheel at an end of the stairway around which said chain passes; a

,chain wheel for each of said steps; and an upper run track for the chain wheels having an end portion at said end of the stairway, said end portion extending beyond a vertical line through the center of the sprocket wheel to a certain point on the bend, said end portion being of a height at said vertical line to cause the line of travel of the centers of the chain wheel axles to intersect said vertical line above the pitch circle of the sprocket wheel and extending gradually downwardly to said certain point where said line of travel meets said pitch circle.

2. A moving stairway comprising; a series of steps; a running gear chain connecting said steps together; a sprocket wheel at an end of the stairway around which said chain passes; a chain wheel for each of said steps, the axis of which coincides with the axis of a roller of the chain; and an upper run track for the chain wheels having an end portion at said end of the stairway extending from a certain point on the incline side of a vertical line through the center of the sprocket wheel to another point on the other side of said vertical line, said end portion being of a height at said certain point such that the line of travel of the axes of said chain wheels at such point is above a horizontal tangent to the pitch circle of the sprocket wheel and extending gradually downwardly from said certain point to said other point where said line of travel merges with said pitch circle.

3. A moving stairway comprising; a series of steps; a running gear chain connecting said steps together; a sprocket wheel at an end of the stairway around which said chain passes; a chain wheel for each of said steps outside the links of the running gear chain, the axle of each chain wheel passing through a roller of the chain; and an upper run track for the chain wheels having an end portion at said end of the stairway extending from a certain point on the incline side of a vertical line through the center of the sprocket wheel to another point on the other side of said vertical line, said end portion being of such height that the axis of each chain wheel as the wheel reaches said certain point is above a horizontal tangent to the pitch circle of the sprocket wheel at the top of the sprocket wheel and extending gradually downwardly from said certain point on a curve such as to cause the line of travel of said axes of such chain wheel to merge with the pitch circle of the sprocket wheel at a point beyond said vertical line.

4. A moving stairway comprising; a series of steps; a running gear chain connecting said steps together; a driving sprocket at the upper end of the stairway around which said chain passes; a chain wheel for each of said steps outside the links of the running gear chain, the axle of each chain wheel passing through a roller of the chain; an upper run track for the chain wheels having a portion thereof at said end of the stairway horizontal up to a certain point on the incline side of a vertical line through the center of said sprocket and an end portion extending from said point to the other side of said vertical line, said horizontal portion being of such height that, when the chain wheels run' thereon, the line of travel of the axes of the chain rollers through which the axles of such chain wheels extend is above a horizontal tangent to the pitch circle of the sprocket at the top of the sprocket and said end portion extendin gradually downwardly from said point to cause the line of travel of said axes of such chain rollers to merge with the pitch circle of the sprocket at a point beyond said vertical line; and means for adjustably supporting said end portion of said upper run track.

5. A moving stairway comprising; a series of steps; a running gear chain connecting said steps together; a driving sprocket at the upper end of the stairway around which said chain passes; a chain wheel for each of said steps outside the links of the running gear chain, the axle of each chain wheel passing through a roller of the chain; an upper run track for the chain wheels extendingpartially around the bend at said end of the stairway, said track having a portion thereof horizontal up to a certain point on the incline side of a vertical line through the center of the sprocket and an end portion extending from said point to the other side of said vertical line, said horizontal portion being of such height that when the chain wheels run thereon, the line of travel of the axes of the chain rollers through which the axles of such chain wheels extend is above a horizontal tangent to the pitch circle of the sprocket at the top of the sprocket and said end portion extending gradually downwardly from said horizontal portion on a curve such that the line of travel of said axes of such chain rollers on said curve is substantially tangent at one end to said line of travel of said axes on said horizontal portion of said track and at the other end to the pitch circle of said sprocket at a point on said other side of said vertical line; and means for adjusting the height of said end portion at said other end thereof.

6. A moving stairway comprising; a series of steps; a running gear chain connecting said steps together; a sprocket wheel at an end of the stairway around which said chain passes; a chain wheel for each of said steps, there being a roller in said chain corresponding to each chain wheel; and a return run track for the chain wheels having a portion which is curved in a direction opposite to that of the pitch circle of said sprocket wheel atthe bottom of the sprocketwheel, said curved portion extending from a point beneath said sprocket wheel for a Certain distance toward the incline to receive said chain wheels after the corresponding chain rollers leave the sprocket wheel, the highest point of said curved portion being on the incline side of a vertical line through the center of the sprocket Wheel and the degree of curvature being such as to maintain each chain wheel on the track once it has engaged the same after the corresponding chain roller has left the sprocket Wheel.

7. A moving stairway comprising; a series of steps; a running gear chain connecting said steps together; a driving sprocket at an end of the stairway around which said chain passes; a chain wheel for each of said steps outside the links of the running gear chain, the axle of each chain wheel passing through a roller of the chain; and a return run track for the chain wheels having an inclined portion and a curved portion, the direction of curvature of said curved portion being opposite to that of the pitch circle of said sprocket at the bottom of the sprocket, said curved portion extending from said inclined portion to a line through the center of the sprocket and normal tothe line of curvature of the curved portion, the line of curvature of the curved portion being tangent to the line of incline of the inclined portion at the point of joinder of said portions and being also tangent at said normal line to the arc of a circle swung from the center of the sprocket at a radius such as to allow a small clearance for the chain wheels from the track at that point, the radius of curvature of the curved portion being at least the number of links in the chain between adjacent chain wheels times the pitch radius of the sprocket but not greater than that which would cause insufiicient downward force to be exerted on each chain wheel to maintain it on the track.

SAMUEL GUSTAVE MARGLES. 

